Email management - saving emails and attaching emails (apple mail)

Hello

I'm looking for an easy way to manage my emails. I need to save emails to a folder and attach emails to other emails.

The simplest way would be to 'drag and drop' but I am finding this very unreliable and I experience a variety of problems eg -

• 'drag and drop' from mail to Finder => no content in file
• 'drag and drop' from mail to new mail message => no content in attachment after sending
• 'file save as' from mail to Finder => content in file in folder but no content in the same file after attaching it to an email and sending
• etc

Another problem is that the behaviour is inconsistent and the error is not always repeatable.

I also want to move the file from Apple Mail to Finder not copy if possible.

Surely there is an easy way to manage email records?

Thanks